Sinking and drainage pump units



Feb. 9, 1960 K. G. ISAKSSON SINKING AND DRAINAGE PUMP UNITS 2Sheets-Sheet 1 Filed April 17, 1956 Feb. 9, 1960 K. G. ISAKSSON smxmcAND DRAINAGE PUMP UNITS 2 Sheets-Sheet 2 Filed. April 1'7, 19562,924,119 SINKING AND DRAINAGE PUMP UNITS Application April 17, 1956,Serial No. 578,620

1 Claim. (Cl. 103-87) This invention relates to sinking and drainagepump units adapted to be immersed in a water body tobe drained, whileresting on the bed of said water body. Such pump units may for instancebe of the type including a watertight electric motor enclosed in a pumpcasing, so that the whole motor-pump unit may be immersed in the water.The pump unit is provided with an inlet opening at its lower end and theinlet opening is covered by a screen or a perforated plate to preventthe entry of large particles of foreign matter into the pump channels.

Pumps of this type have generally been suspended on wires or chains froma stand or the like, so as to keep the perforated bottom plate near thebottom of the cavity to be drained. However, at certain conditions ofthe soil, for instance loose sand or clay, it is often impossible toerect a stand and the pump unit must rest on the loose ground on the bedof the cavity. Under these circumstances the pump unit has been found todig into the soil when running and moreover the pump unit is often veryunsteady so that it will not stand upright for a long period.Furthermore, under certain conditions of the loose soil or when the bedof the cavity is covered by a layer of sludge the perforations tend tobe choked up by the particles carried by the input water stream.

The main object of this invention is to provide supporting means for thepump unit, said supporting means permitting the pump to rest steadily onthe ground, while keeping its bottom screen or perforated plate at a predetermined distance from the bed of the cavity to be drained, even ifsaid bed consists of very loose sand, clay or the like.

According to the invention a sinking and drainage pump unit of the kinddescribed above includes a support member in the form of a closed figurecorresponding in shape substantially to the periphery of the screen orperforated plate secured to the screen or perforated plate and disposedin a plane parallel to and spaced from it so as to form an entry slotbetween the screen or perforated plate and the support member.

In use, the support member rests upon the bed of the cavity to bedrained and the pump unit is steadily supported by the support memberwithout any tendency towards digging into the bed.

The width of said slot is important and it has been found that in orderto obtain satisfying results the width should be from 1 to 10 percent ofthe maxim-um transverse dimension of said screen or perforated plate. Inorder to obtain the best results the definite limits must be determinedfor each special case, taking into consideration the size of the pumpand of the screen or perforated plate as well as the pump deliverycapacity.

As by way of example it may be mentioned that with a diameter of thescreen or perforated plate of about 16 inches and a delivery of about265 gallons per minute the best result was obtained with a slot having awidth of about 95 inch while a width of about W inch did not give thedesired result.

Preferably, deflector members are provided within the Peed S tes. Paten1 support member for guiding the water uniformly over the screen orperforated plate and preventing turbulences beneath said screen orperforated plate.

The invention will be described in the following with reference to theaccompanying drawings which'illustrate preferred embodiments given as anexample only without restricting the invention.

In the drawings:

Figure 1 is an elevational view partially in section of anembodiment ofthe invention,

Figure 2 is a similar view showing a somewhat modified bottom plate, and

Figure 3 is a plan undersize view showing deflector means according tomy invention.

In Fig. l of the drawings 1 designates a casing enclosing a pump unitspaced from said casing 1 so as to form a water passage from the lowerend of the casing 1 to a hose connection 2 at the top thereof. Said pumpunit includes a centrifugal pump, generally indicated by 3 having itshousing secured to said casing 1 by means of bolts 4. The pump housingsupports a driving motor watertightly enclosed in a casing 5. A cable 6containing electric conductors is passed through the top of said casings5 and 1 to be connected to a suitable electric source.

An eye bolt 7 is screwed to the top of the casings 1 and 5 for liftingthe pump device.

Said centrifugal pump 3 has a central inlet opening 8. Said inletopening 8 is covered by a perforated screen or bottom plate 9. Saidscreen or bottom plate 9 may be somewhat cup shaped with low verticalmargin portions which may also be perforated. However, the largest areafor water to pass through is constituted by the proper bottom surface.The bottom plate may be plane as shown in Fig. 2 or concave as shown inFig. 1, secured by bolts 10.

The under side of the perforated plate 9 is provided with deflectormembers 11 arranged in the form of a cross formed by ribs, flat ironbarsor the like arranged perpendicular to the perforated plate. shown inFig. 3. The length of the ribs or bars corresponds to the diameter ofthe perforated plate 9, and their ends are secured to a support ring orsupport member 12 of circular ring form, of a diameter substantiallyequal to the diameter of the screen or perforated plate 9. The member 12is located at a distance from said perforated plate 9 so as to form anannular slot A therebetween. Although the support ring 12 of relativelylarge cross section is shown as a tube, it may be made of solid materialand may have different cross sections provided it presents a suitablylarge bearing surface area against the ground. The radial or crossedbars 11 are shown as being welded to the perforated plate 9, but may befastened in any other suitable manner, for instance by lugs 13 and bolts14 (Fig. 2), or may be formed integral with said perforated plate 9.

It is to be noted that the crossed bars 11 may be replaced by otherforms of deflector members for preventing turbulence under theperforated plate 9 while distributing the water uniformly over the wholeperforated surface.

The device acts in the following manner when the support member 12 rests.on loose ground forming the bed of a cavity to be drained. At thebeginning fine particles from the loose ground inside the support ring12 are carried away with the water sucked by the pump so that a smallhollow is formed within said support ring 12. The ring itself restshowever on a layer undisturbed by the water stream. After this firstremoval of particles of sand, sludge, clay or the like, it has beenfound that any removal of such particles within said ring 12 ceases sothat the supporting ring 12 rests on a compact portion of the ground andkeeps the pump unit and its inlet screen 7 Patented Feb. 9,

Said cross is bestv or perforatedplate on; jconstant'leveliaboye theground. 8 i

The ring 12 is drawn into close contact with theg'round by the action ofthe pumpgiso that all Water sucked in will pass through said annularslot A.-

-Altbough he inyention h'asbe e'n descrihed'yvith reference to anembodiment iniwhichlthe. screen or per-for such as oval or rectangular.

I claim:

A sinking and drainage pump innit comprising, in combination, abellshaped housing having an open bottom face including an inlet openinga'centrifugal pump and its 8 a drivingrnotor enclosedin saidhousing,said unit being adapted to be entirely immersed in a liquid body to bedrained; a screen of substantial transverse dimension covering thebottom face of saiclbell-shaped housing, an

endless bar-shaped ground engaging support member corresponding in shapeto the periphery of said screen;

ated platefl andthe support member 12 are circular, it is equallyapplicable to pump units having other shapes,

di l fi w na Pete se ure to d n and said ground engaging supportnie'n'aberrs'pecti'v'ly, therebyIholding the screen gnniformly spacedfrom the ground engaging support member and defining a substantiallyunobstructed endless entry slot with a height of be-, tween one and tenpercent of the transverse dimension of the screen. i

j References emit thefileof this flzltiit QNITED sTA'rEsr TENrs mp!

